1.noun(Roman Catholic theology, since circa 400 A.D.) The place where innocent souls exist temporarily until they can enter heaven, notably those of the saints who died before the advent of Christ (limbus patruum) and those of unbaptized but innocent children (limbus infantum).
2.noun(by extension, since the 16th century) Any in-between place, state or condition of neglect or oblivion which results in an unresolved status, delay or deadlock.
"My application has been stuck in bureaucratic limbo for two weeks."